New motors give industry plenty to 'torque' about
New motors give industry plenty to "torque" about
A new concept in motor design has been unveiled by Control Techniques Dynamics Ltd, with the launch of the company's Unimotor range of brushless AC servo motors. The new motors have been produced to satisfy the high demands of machine tool and automation industries where modern servo-drive systems provide greater motor speed control and positioning capability.
The Unimotor range are three phase, 6- or 8-pole, permanently excited synchronous motors, exhibiting a sinusoidal back EMF characteristic. They have been designed to supply high torque with either low or high rotor inertia and minimal cogging torque. Thermal performance is improved by the unique, new "finned" motor housing, manufactured in high strength alloy casting to radiate and convect heat.
Traditionally, naturally ventilated motors have relatively smooth frame surfaces, with cylindrical or square frames, or a combination of the two. The idea at CT Dynamics was to add radial fins to the motor in order to increase the natural convection from the motor surface. The single piece integral construction permits accurate bearing to housing alignment and maintains air gap concentricity. This optimizes output and reduces cogging torque while the compact design gives increased torsional stiffness.
Laminations and coils are designed for optimum efficiency and low harmonic distortion. Combined with the high energy magnets and a choice of rotor inertias, CT Dynamics' Unimotor provides excellent dynamic performance to suit all requirements. The use of specially developed coil wire gives previously unheard of reliability when used with modern, high frequency PWM (pulse width modulation) servo drives. Commutation and position feedback is provided by an incremental encoder as standard, giving high resolution and accuracy, resulting in excellent speed and position control. Alternative feedback devices, optionally available, include a single or multi-turn sine/cos encoder or a resolver feedback for high temperature applications.
A high performance range of planetary gearboxes are offered as an optional feature. Matched with the Unimotor, the gearbox gives high torque output with very low backlash. The inherent torsional stiffness of the precision planetary gears and the rugged UM series servo motor ensures the stable control of highly dynamic loads. Compact in design and with high system efficiency, the range offers the system integrator the ideal solution for precision machine motion.
Renowned for its high quality rotating components used in bespoke military applications, Control Techniques Dynamics anticipates that its new Unimotor range will prove of interest for use in a spectrum of applications. These will include machine tool applications, handling systems, robots, positioning systems and a variety of OEM applications requiring the highest reliability and performance.
Further information can be obtained from Control Techniques Dynamics Ltd, South Way, Walworth Industrial Estate, Andover, Hants SP10 5AB. Tel: 01264 324155.
